European Patent Application EP 378 015 describes breathable waterproof films that are made of polyetheresteramides which may be adhesively bonded by heating or with the aid of an adhesive onto fabric, leather, or plastic.
European Patent Application EP 0 560 630 breathable waterproof materials that consist (Example 6) of two coextruded films (1) and (2). To each face of the film thus obtained, a nonwoven is adhesively bonded with the aid of a polyurethane-based adhesive in solution in trichloroethylene. The film (1) is a mixture of polyetheresteramide, of polyamide 6, and of polyethylene grafted with maleic anhydride. The film (2) consists of another polyetheresteramide. A polyamide-based nonwoven is adhesively bonded on the side of the film (1). A polyester nonwoven is adhesively bonded on the side of the film (2).
Example 7 of the same prior art describes the same two-layer material consisting of coextruded films (1) and (2), but a nonwoven made of polyester/polyethylene is adhesively bonded on the side of the film (1) and a nonwoven made of polyester is adhesively bonded on the side of the film (2).
This material is employed for making garments by arranging the polyester/polyethylene nonwoven on the inside of the garment and the polyester nonwoven towards the outside of the garment. The material makes the garment permeable to water vapour and impervious to water and to blood splashed from the outside towards the garment, thus protecting the person wearing the garment.
European Patent Application EP 459 862 describes films that consist of a mixture of polyetheresteramide and of a modified polyolefin chosen from: copolymers of ethylene and of vinyl acetate, optionally maleinized; copolymers of ethylene and of (meth)acrylic acid; copolymers of ethylene, of vinyl acetate, and optionally of alkyl (meth)acrylate; and copolymers of ethylene, of alkyl (meth)acrylate, and optionally of maleic anhydride.
These films may be adhesively bonded onto fabrics and nonwovens.
Example 8-1 shows a film that consists of a mixture of a polyetheresteramide and of a maleinized EVA adhesively bonded onto a textile.
The thickness of the films described in EP 459 862 is from 100 to 500 .mu.m. They are not breathable waterproof films.
The breathable waterproof films of the prior art that are based upon polyetheresteramides have the disadvantage, when they are very permeable, of having a high moisture uptake which results in their swelling and makes them fragile.
Films made of blend of polyetheresteramides and polyamides are not supple enough and adhesively bond with difficulty to nonwovens.